The present invention relates to a data transmission system and data transmission method using one-way communication.
Recently, cell phones have a near-field communication function such as a wireless LAN or Bluetooth®. In the future, cell phones will be equipped with a one-way communication function of receiving data transmitted by light generated by an LED illumination light or the like.
As various communication means are installed in cell phones, the chance to connect a cell phone to a communication network and transmit setting information of application software to the cell phone increases in accordance with the position and situation.
Conventionally, a server which transmits various kinds of setting information performs user authentication at a timing when various kinds of setting information are transmitted, and determines whether a cell phone has the right to receive various kinds of setting information.
For example, reference 1 (Japanese Patent Laid-Open No. 6-177888) proposes a system which, when connection setting information to a communication network is not stored in a computer system upon activation, requests a gateway to transmit connection setting information to the communication network and receives the connection setting information.
Reference 2 (Japanese Patent Laid-Open No. 2002-318788) proposes a terminal which receives an IC card on which connection information to a communication network is stored, reads out the connection information to the communication network that is stored in the mounted IC card, and is connected to the communication network.
Reference 3 (Japanese Patent Laid-Open No. 2000-224156) proposes a system in which the first apparatus transmits an instruction and encryption information to the second apparatus by one-way communication, and the second apparatus transmits, to the first apparatus, information encrypted using the encryption information received from the first apparatus.
In one-way communication using an LED illumination light or the like, the server cannot perform user authentication in transmitting various kinds of setting information. It is difficult to transmit setting information of a use condition which changes depending on the user.
A cell phone is considered to receive various kinds of setting information via a cell phone communication network by using a communication method such as PDC (Personal Digital Cellular) or CDMA (Code Division Multiple Access). A location where the user wants to receive information does not always fall within the service providing range of cell phone communication. It is an important subject to implement a method of using one-way communication to transmit data such as various kinds of setting information corresponding to the user of a cell phone.
The system described in reference 1 uses two-way communication, and cannot use one-way communication to transmit information corresponding to the user. This system cannot be applied to a system used in a situation in which no two-way communication can be done.
The terminal described in reference 2 cannot automatically receive connection information to a communication network because the user inserts/removes an IC card. The terminal cannot be connected to a communication network whose connection information is not stored in user's IC card.
The system described in reference 3 does not consider the use in a situation in which two-way communication is impossible between the first and second apparatuses. The system cannot be applied to a system used in a situation in which communication from the second apparatus to the first apparatus is impossible.